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ABSTRACT: Typical brain development includes coordinated changes in both white matter (WM) integrity and cortical thickness (CT). These processes have been shown to be disrupted in schizophrenia, which is characterized by abnormalities in WM microstructure and by reduced CT. The aim of this study was to identify patterns of association between WM markers and cortex-wide CT in healthy controls (HCs) and patients with schizophrenia (SCZ). Using diffusion tensor imaging and structural magnetic resonance imaging data of the Mind Clinical Imaging Consortium study (130 HC and 111 SCZ), we tested for associations between (a) fractional anisotropy in selected manually labeled WM pathways (corpus callosum, anterior thalamic radiation, and superior longitudinal fasciculus) and CT, and (b) the number of lesion-like WM regions ("potholes") and CT. In HC, but not SCZ, we found highly significant negative associations between WM integrity and CT in several pathways, including frontal, temporal, and occipital brain regions. Conversely, in SCZ the number of WM potholes correlated with reduced CT in the left lateral temporal gyrus, left fusiform, and left lateral occipital brain area. Taken together, we found differential patterns of association between WM integrity and CT in HC and SCZ. Although the pattern in HC can be explained from a developmental perspective, the reduced gray matter CT in SCZ patients might be the result of focal but spatially heterogeneous disruptions of WM integrity.
Schizophrenia Bulletin 05/2013; · 8.80 Impact Factor
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ABSTRACT: Patients with schizophrenia show widespread cortical thickness reductions throughout the brain. Likewise, reduced expression of the γ-Aminobutyric acid (GABA) synthesizing enzyme glutamic acid decarboxylase (GAD1) and a single nucleotide polymorphism (SNP) rs3749034 in the corresponding gene have been associated with schizophrenia. We tested whether this SNP is associated with reduced cortical thickness, an intermediate phenotype for schizophrenia. Because of the well known interactions between the GABAergic and dopaminergic systems, we examined whether associations between GAD1 rs3749034 and cortical thickness are modulated by the catechol-O-methyltransferase (COMT) Val158Met genotype. Structural MRI and genotype data was obtained from 94 healthy subjects enrolled in the Mind Clinical Imaging Consortium study to examine the relations between GAD1 genotype and cortical thickness. Our data show a robust reduction of cortical thickness in the left parahippocampal gyrus (PHG) in G allele homozygotes of GAD1 rs3749034. When we stratified our analyses according to the COMT Val158Met genotype, cortical thickness reductions of G allele homozygotes were only found in the presence of the Val allele. Genetic risk variants of schizophrenia in the GABAergic system might interact with the dopaminergic system and impact brain structure and functioning. Our findings point to the importance of the GABAergic system in the pathogenesis of schizophrenia.
Journal of psychiatric research 04/2013; · 3.72 Impact Factor
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ABSTRACT: AIM: Working memory deficits have been shown to be present in children and adolescents with schizophrenia and attention deficit hyperactivity disorder. Considering the differences in clinical characteristics between these disorders, it was the goal of this study to assess differences in the specific components of working memory in children and adolescents with psychosis and attention deficit hyperactivity disorder. METHODS: Children and adolescents (age range 8-20 years) with either a non-affective psychotic disorder (n = 25), attention deficit hyperactivity disorder (n = 33) and controls (n = 58) were administered an oculomotor delayed-response task using both a recall and a control condition. Memory-guided saccades were measured during delay periods of 2, 8 and 20 s. RESULTS: Although both clinical groups were less accurate than controls, there was no evidence of a disproportionate impairment in recall. In addition, there was no evidence of a delay-dependent impairment in psychosis; however, there was a delay-dependent impairment in attention deficit hyperactivity disorder when corrective saccades were included. Speed of information processing was correlated with distance errors in psychosis, suggesting that speed of encoding the stimulus location may have constrained the accuracy of the saccades. CONCLUSIONS: Our findings support impairments during encoding in the psychosis group and a delay-dependent deficit in the attention deficit hyperactivity disorder group.
Early Intervention in Psychiatry 02/2013; · 0.92 Impact Factor
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ABSTRACT: Despite interest in dopamine's role in emotion-based decision-making, few reports of the effects of dopamine manipulations are available in this area in humans. This study investigates dopamine's role in emotion-based decision-making through a common measure of this construct, the Iowa Gambling Task (IGT), using Acute Tyrosine Phenylalanine Depletion (ATPD). In a between-subjects design, 40 healthy adults were randomized to receive either an ATPD beverage or a balanced amino acid beverage (a control) prior to completing the IGT, as well as pre- and post- manipulation blood draws for the neurohormone prolactin. Together with conventional IGT performance metrics, choice selections and response latencies were examined separately for good and bad choices before and after several key punishment events. Changes in response latencies were also used to predict total task performance. Prolactin levels increased significantly in the ATPD group but not in the control group. However, no significant group differences in performance metrics were detected, nor were there sex differences in outcome measures. However, the balanced group's bad deck latencies speeded up across the task, while the ATPD group's latencies remained adaptively hesitant. Additionally, modulation of latencies to the bad decks predicted total score for the ATPD group only. One interpretation is that ATPD subtly attenuated reward salience and altered the approach by which individuals achieved successful performance, without resulting in frank group differences in task performance.
Pharmacology Biochemistry and Behavior 01/2013; · 2.53 Impact Factor
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Jing Sui,
Hao He,
Godfrey D Pearlson,
Tülay Adali,
Kent A Kiehl,
Qingbao Yu,
Vince P Clark,
Eduardo Castro, Tonya White,
Bryon A Mueller,
Beng C Ho,
Nancy C Andreasen,
Vince D Calhoun
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ABSTRACT: Multi-modal fusion is an effective approach to better understand brain diseases. However, most such instances have been limited to pair-wise fusion; because there are often more than two imaging modalities available per subject, there is a need for approaches that can combine multiple datasets optimally. In this paper, we extended our previous two-way fusion model called "multimodal CCA+joint ICA", to three or N way fusion, that enables robust identification of correspondence among N data types and allows one to investigate the important question of whether certain disease risk factors are shared or distinct across multiple modalities. We compared "mCCA+jICA" with its alternatives in a 3-way fusion simulation and verified its advantages in both decomposition accuracy and modal linkage detection. We also applied it to real functional Magnetic Resonance Imaging (fMRI)-Diffusion Tensor Imaging (DTI) and structural MRI fusion to elucidate the abnormal architecture underlying schizophrenia (n=97) relative to healthy controls (n=116). Both modality-common and modality-unique abnormal regions were identified in schizophrenia. Specifically, the visual cortex in fMRI, the anterior thalamic radiation (ATR) and forceps minor in DTI, and the parietal lobule, cuneus and thalamus in sMRI were linked and discriminated between patients and controls. One fMRI component with regions of activity in motor cortex and superior temporal gyrus individually discriminated schizophrenia from controls. Finally, three components showed significant correlation with duration of illness (DOI), suggesting that lower gray matter volumes in parietal, frontal, temporal lobe and cerebellum are associated with increased DOI, along with white matter disruption in ATR and cortico-spinal tracts. Findings suggest that the identified fractional anisotropy changes may relate to the corresponding functional/structural changes in brain that are thought to play a role in the clinical expression of schizophrenia. The proposed "mCCA+jICA" method showed promise for elucidating the joint or coupled neuronal abnormalities underlying mental illnesses and improves our understanding of the disease process.
NeuroImage 10/2012; · 5.89 Impact Factor
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ABSTRACT: There is considerable evidence implicating brain white matter (WM) abnormalities in the pathophysiology of schizophrenia; however, the spatial localization of WM abnormalities reported in the existing studies is heterogeneous. Thus, the goal of this study was to quantify the spatial characteristics of WM abnormalities in schizophrenia. One hundred and fourteen patients with schizophrenia and 138 matched controls participated in this multisite study involving the Universities of Iowa, Minnesota, and New Mexico, and the Massachusetts General Hospital. We measured fractional anisotropy (FA) in brain WM regions extracted using 3 different image-processing algorithms: regions of interest, tract-based spatial statistics, and the pothole approach. We found that FA was significantly lower in patients using each of the 3 image-processing algorithms. The region-of-interest approach showed multiple regions with lower FA in patients with schizophrenia, with overlap at all 4 sites in the corpus callosum and posterior thalamic radiation. The tract-based spatial statistic approach showed (1) global differences in 3 of the 4 cohorts and (2) lower frontal FA at the Iowa site. Finally, the pothole approach showed a significantly greater number of WM potholes in patients compared to controls at each of the 4 sites. In conclusion, the spatial characteristics of WM abnormalities in schizophrenia reflect a combination of a global low-level decrease in FA, suggesting a diffuse process, coupled with widely dispersed focal reductions in FA that vary spatially among individuals (ie, potholes).
Schizophrenia Bulletin 09/2012; · 8.80 Impact Factor
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Kathryn R Cullen,
Stuart Wallace,
Vincent A Magnotta,
Jeremy Bockholt,
Stefan Ehrlich,
Randy L Gollub,
Dara S Manoach,
Beng C Ho,
Vincent P Clark,
John Lauriello,
Juan R Bustillo,
S Charles Schulz,
Nancy C Andreasen,
Vince D Calhoun,
Kelvin O Lim, Tonya White
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ABSTRACT: The majority of patients with schizophrenia smoke cigarettes. Both nicotine use and schizophrenia have been associated with alterations in brain white matter microstructure as measured by diffusion tensor imaging (DTI). The purpose of this study was to examine fractional anisotropy (FA) in smoking and non-smoking patients with schizophrenia and in healthy volunteers. A total of 43 patients (28 smoking and 15 non-smoking) with schizophrenia and 40 healthy, non-smoking participants underwent DTI. Mean FA was calculated in four global regions of interest (ROIs) (whole brain, cerebellum, brainstem, and total cortical) as well as in four regional ROIs (frontal, temporal, parietal and occipital lobes). The non-smoking patient group had a significantly higher intellectual quotient (IQ) compared with the patients who smoked, and our results varied according to whether IQ was included as a covariate. Without IQ correction, significant between-group effects for FA were found in four ROIs: total brain, total cortical, frontal lobe and the occipital lobe. In all cases the FA was lower among the smoking patient group, and highest in the control group. Smoking patients differed significantly from non-smoking patients in the frontal lobe ROI. However, these differences were no longer significant after IQ correction. FA differences between non-smoking patients and controls were not significant. Among smoking and non-smoking patients with schizophrenia but not healthy controls, FA was correlated with IQ. In conclusion, group effects of smoking on FA in schizophrenia might be mediated by IQ. Further, low FA in specific brain areas may be a neural marker for complex pathophysiology and risk for diverse problems such as schizophrenia, low IQ, and nicotine addiction.
Psychiatry Research 03/2012; 201(2):152-8. · 2.52 Impact Factor
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ABSTRACT: Human brains are highly convoluted surfaces with multiple folds. To characterize the complexity of these folds and their relationship with neurological and psychiatric conditions, different techniques have been developed to quantify the folding patterns, also known as the surface complexity or gyrification of the brain. In this study, the authors propose a new geometric approach to measure the gyrification of human brains from magnetic resonance images. This approach is based on intrinsic 3D measurements that relate the local brain surface area to the corresponding area of a tightly wrapped sheet. The authors also present an adaptation of this technique in which the geodesic depth is incorporated into the gyrification computation. These gyrification measures are efficiently and accurately computed by solving geometric partial differential equations. The presentation of the geometric framework is complemented with experimental results for brain complexity in typically developing children and adolescents. Using this novel approach, the authors provide evidence for a gradual decrease in brain surface complexity throughout childhood and adolescence. These developmental differences occur earlier in the occipital lobe and move anterior as children progress into young adulthood. Hum Brain Mapp, 2012. © 2012 Wiley Periodicals, Inc.
Human Brain Mapping 02/2012; · 5.88 Impact Factor
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ABSTRACT: Literature supporting a relationship between emotions and regulation of blood pressure dates back to the early 1900s. Theoretical explanations of the pathophysiology of the correlation have centered on several possible trajectories, the most likely being cardiovascular reactivity to stress. Prospective studies have demonstrated that chronic stress and enduring traits such as defensiveness and anxiety, impacts the development of hypertension. An analysis of 195 genetic males seeking contrary hormones for treatment of gender dysphoria revealed a significantly increased prevalence of hypertension in this cohort. The authors attribute this increased prevalence to the known effects of emotional disclosure on health and conclude that the inhibition of emotional expressiveness is significant in the etiology and maintenance of essential hypertension in this population. As hypertension is associated with morbidity and mortality, the implications for the family medicine physician treating gender nonconforming individuals and other patients in the context of a general medical practice will be discussed.
International journal of family medicine. 01/2012; 2012:492718.
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ABSTRACT: It has long been known that specific visual frequencies result in greater blood flow to the striate cortex. These peaks are thought to reflect synchrony of local neuronal firing that is reflective of local cortical networks. Since disrupted neural connectivity is a possible etiology for schizophrenia, our goal was to investigate whether localized connectivity, as measured by aberrant synchrony, is abnormal in children and adolescents with schizophrenia. Subjects included 25 children and adolescents with schizophrenia and 39 controls matched for age and gender. Subjects were scanned on a Siemens 3 Tesla Trio scanner while observing flashing checkerboard presented at either 1, 4, 8, or 12 Hz. Image processing included both a standard GLM model and a Fourier transform analysis. Patients had significantly smaller volume of activation in the occipital lobe compared to controls. There were no differences in the integral or percent signal change of the hemodynamic response function for each of the four frequencies. Occipital activation was stable during development between childhood and late adolescence. Finally, both patients and controls demonstrated an increased response between 4 and 8 Hz consistent with synchrony or entrainment in the neuronal response. Children and adolescents with schizophrenia had a significantly lower volume of activation in the occipital lobe in response to the flashing checkerboard task. However, features of intact local connectivity in patients, such as the hemodynamic response function and maximal response at 8 Hz, were normal. These results are consistent with abnormalities in regional connectivity with preserved local connectivity in early-onset schizophrenia.
Human Brain Mapping 06/2011; 33(8):1803-11. · 5.88 Impact Factor
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ABSTRACT: Children and adolescents who develop schizophrenia tend to have greater symptom severity than adults who develop the illness. Since the brain continues to mature into early adulthood, developmental differences in brain structure and function may provide clues to the underlying neurobiology of schizophrenia. With an emerging body of evidence supporting disrupted connectivity contributing to the underlying pathophysiology of schizophrenia, it was our goal to assess differences in functional connectivity in children and adolescents who develop schizophrenia. Participants included a total of 28 children and adolescents (14 patients with schizophrenia and 14 age- and gender-matched controls). All subjects underwent a functional magnetic resonance imaging scan involving a modified Sternberg Item Recognition Paradigm with 3 working memory (WkM) loads. Patients had poorer performance at all 3 WkM loads without a load by diagnosis interaction. Functional imaging results demonstrated 3 specific brain networks disrupted in children and adolescents with schizophrenia. These networks include 1) the anterior cingulate and the temporal lobes, bilaterally; 2) the cerebellum with subcortical regions; and 3) the occipital lobe and the cerebellum. Patients with early-onset schizophrenia demonstrate abnormal functional connectivity in networks involving limbic, temporal lobe, cerebellum, and early visual processing streams.
Cerebral Cortex 03/2011; 21(3):510-8. · 6.54 Impact Factor
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ABSTRACT: Similar to adults, children and adolescents with schizophrenia present with significant working memory (WkM) deficits. However, unlike adults, findings of abnormal activity in the prefrontal cortex in early-onset schizophrenia (EOS) are not consistently reported. Since WkM continues to develop through adolescence and into early adulthood, patterns of activation in adolescents may be different than those found in adults. The goal of this study was to evaluate the functional neurobiology of WkM in patients with EOS.
Participants included 22 patients with EOS (mean age 15±2.8 years) and 24 controls (mean age 15.0±3.0 years). Diagnoses were confirmed using the KIDDIE-SADS-PL. All subjects underwent a functional MRI paradigm involving a visuospatial working memory task with three separate loads.
The behavioral results demonstrated deficits in EOS patients at all three WkM loads. On functional imaging, EOS patients demonstrated increased activation in the anterior cingulate cortex (ACC), medial temporal lobe structures, the insula, and bilateral lateral temporal lobes.
Patients with EOS demonstrate increased activity in limbic structures and regions involved in processing primary and secondary sensory information. In addition, EOS patients had load dependent decreased activity in the parietal lobe. Unlike studies in adults, we did not find that EOS patients had activation differences in the frontal cortical regions. One possibility is that abnormalities in PFC function are related to secondary downstream or developmental processes which are 'unmasked' during development. Finally, our findings support growing evidence that EOS patients have aberrations in the limbic and temporal lobe regions.
Biological Psychiatry 02/2011; 125(2-3):118-28. · 8.28 Impact Factor
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ABSTRACT: There is emerging evidence for a connection between the surface morphology of the brain and its underlying connectivity. The foundation for this relationship is thought to be established during brain development through the shaping influences of tension exerted by viscoelastic nerve fibers. The tension-based morphogenesis results in compact wiring that enhances efficient neural processing. Individuals with schizophrenia present with multiple symptoms that can include impaired thought, action, perception, and cognition. The global nature of these symptoms has led researchers to explore a more global disruption of neuronal connectivity as a theory to explain the vast array of clinical and cognitive symptoms in schizophrenia. If cerebral function and form are linked through the organization of neural connectivity, then a disruption in neural connectivity may also alter the surface morphology of the brain. This paper reviews developmental theories of gyrification and the potential interaction between gyrification and neuronal connectivity. Studies of gyrification abnormalities in children, adolescents, and adults with schizophrenia demonstrate a relationship between disrupted function and altered morphology in the surface patterns of the cerebral cortex. This altered form may provide helpful clues in understanding the neurobiological abnormalities associated with schizophrenia.
Development and Psychopathology 02/2011; 23(1):339-52. · 4.40 Impact Factor
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ABSTRACT: Schizophrenia is a heterogeneous neurodevelopmental disorder. Patients with high levels of negative symptoms have been identified as a specific subtype, but little is known about how the neurodevelopmental course may differ in this group. This study aimed to characterize developmental trajectories of premorbid social withdrawal and cognitive decline between patients with high versus low levels of negative symptoms in youth with schizophrenia-spectrum disorders.
A standardized timeline was used to delineate the emergence of psychosis, social withdrawal, and cognitive decline in 52 subjects aged 8 to 19 with schizophrenia (n=36), schizophreniform (n=6), or schizoaffective disorder (n=10). The sample was divided into subgroups of high- (n=26) versus low- (n=26) negative symptoms, and developmental trajectories of premorbid symptoms were compared between groups.
Mean ages for emergence of social withdrawal, cognitive decline, and psychosis were 11.1 years (SD=2.5), 11.9 (SD=4.4) and 13.2 years (SD=1.2), respectively. In the high-negative symptom group, the premorbid developmental trajectory for social withdrawal was more protracted. This group also had more severe cognitive decline at the onset of psychosis, but the premorbid trajectories for cognitive decline did not differ significantly between groups.
This work documents a more severe and protracted trajectory of premorbid social withdrawal in patients with high levels of negative symptoms in comparison to those with low-negative symptoms. The findings reported here are supportive of the hypothesis that patients with illness characterized by high levels of negative symptoms may represent a subgroup with distinct neurodevelopmental abnormalities.
Clinical Schizophrenia & Related Psychoses 01/2011; 4(4):229-38.
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ABSTRACT: Cognitive deficits have been well described in adolescents with schizophrenia, but little is known about the neuroanatomical basis of these abnormalities. The authors examined whether neuropsychological deficits observed in adolescents with schizophrenia were associated with cortical gray matter volume deficits. Volumes of the superior frontal gyrus, anterior cingulate gyrus and orbital frontal lobe were outlined manually from contiguous MR images and automatically segmented into gray and white matter in 52 patients and 48 healthy volunteers. Subjects received a comprehensive neuropsychological test battery, assessing five different functional domains: executive, attention, verbal memory, motor and sensory motor. Children and adolescents with schizophrenia were found to have lower total cortical and lower superior frontal gyrus gray matter volumes and lower test scores across all functional domains compared to healthy volunteers. Among patients, the lower total cortical gray matter volume was associated with worse functioning on the attention and motor domains. Our findings point to widespread, perhaps multifocal, pathology as contributing to cognitive dysfunction in adolescents with schizophrenia.
Progress in Neuro-Psychopharmacology and Biological Psychiatry 01/2011; 35(4):939-43. · 3.25 Impact Factor
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Andrew M Michael,
Margaret D King,
Stefan Ehrlich,
Godfrey Pearlson, Tonya White,
Daphne J Holt,
Nancy C Andreasen,
Unal Sakoglu,
Beng-Choon Ho,
S Charles Schulz,
Vince D Calhoun
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ABSTRACT: The brain is a vastly interconnected organ and methods are needed to investigate its long range structure(S)-function(F) associations to better understand disorders such as schizophrenia that are hypothesized to be due to distributed disconnected brain regions. In previous work we introduced a methodology to reduce the whole brain S-F correlations to a histogram and here we reduce the correlations to brain clusters. The application of our approach to sMRI [gray matter (GM) concentration maps] and functional magnetic resonance imaging data (general linear model activation maps during Encode and Probe epochs of a working memory task) from patients with schizophrenia (SZ, n = 100) and healthy controls (HC, n = 100) presented the following results. In HC the whole brain correlation histograms for GM-Encode and GM-Probe overlap for Low and Medium loads and at High the histograms separate, but in SZ the histograms do not overlap for any of the load levels and Medium load shows the maximum difference. We computed GM-F differential correlation clusters using activation for Probe Medium, and they included regions in the left and right superior temporal gyri, anterior cingulate, cuneus, middle temporal gyrus, and the cerebellum. Inter-cluster GM-Probe correlations for Medium load were positive in HC but negative in SZ. Within group inter-cluster GM-Encode and GM-Probe correlation comparisons show no differences in HC but in SZ differences are evident in the same clusters where HC vs. SZ differences occurred for Probe Medium, indicating that the S-F integrity during Probe is aberrant in SZ. Through a data-driven whole brain analysis approach we find novel brain clusters and show how the S-F differential correlation changes during Probe and Encode at three memory load levels. Structural and functional anomalies have been extensively reported in schizophrenia and here we provide evidences to suggest that evaluating S-F associations can provide important additional information.
Frontiers in Human Neuroscience 01/2011; 5:71. · 2.34 Impact Factor
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ABSTRACT: A number of recent studies have combined multiple experimental paradigms and modalities to find relevant biological markers for schizophrenia. In this study, we extracted fMRI features maps from the analysis of three experimental paradigms (auditory oddball, Sternberg item recognition, sensorimotor) for a large number (n=154) of patients with schizophrenia and matched healthy controls. We used the general linear model (GLM) and independent component analysis (ICA) to extract feature maps (i.e. ICA component maps and GLM contrast maps), which were then subjected to a coefficient-constrained independent component analysis (CCICA) to identify potential neurobiological markers. A total of 29 different feature maps were extracted for each subject. Our results show a number of optimal feature combinations that reflect a set of brain regions that significantly discriminate between patients and controls in the spatial heterogeneity and amplitude of their feature signals. Spatial heterogeneity was seen in regions such as the superior/middle temporal and frontal gyri, bilateral parietal lobules, and regions of the thalamus. Most strikingly, an ICA feature representing a bilateral frontal pole network was consistently seen in the ten highest feature results when ranked on differences found in the amplitude of their feature signals. The implication of this frontal pole network and the spatial variability which spans regions comprising of bilateral frontal/temporal lobes and parietal lobules suggests that they might play a significant role in the pathophysiology of schizophrenia.
Neuroinformatics 12/2010; 8(4):213-29. · 2.97 Impact Factor
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ABSTRACT: Deficits in working memory are considered a core feature of schizophrenia and are present early in the course of the illness. Because working memory continues to mature through childhood and into early adulthood, it was the aim of this study to assess developmental trajectories of verbal and visuospatial working memory performance in children and adolescents with schizophrenia. Differences in the developmental trajectories in patients compared with controls may reflect differential effects within specific neural networks involved in working memory performance.
Twenty-six children and adolescents with schizophrenia (age range of 8-19 years) and 37 controls matched on age and gender participated in the study. Modified versions of both a verbal and visuospatial Sternberg Item Recognition Paradigm were administered.
In the three age groups studied, patients performed significantly worse than controls on the verbal working memory tasks. There were significant effects of diagnosis and load on the verbal Sternberg, with patients performing worse than controls. However, there was no diagnosis by load interactions. Similar findings were present for the visuospatial Sternberg, except for the youngest age group. The 8- to 12-year-old patients had a disproportionately lower performance on the verbal working memory task than on the visuospatial task.
Our findings support disruptions in shared verbal and visuospatial working memory networks, such as those supporting encoding processes, in children and adolescents with schizophrenia. We also found specific deficits in non-shared verbal working memory performance in childhood-onset schizophrenia.
Early Intervention in Psychiatry 11/2010; 4(4):305-13. · 0.92 Impact Factor
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International Journal of Transgenderism 07/2010; 12(3):139-143.
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ABSTRACT: Collection of multiple-task brain imaging data from the same subject has now become common practice in medical imaging studies. In this paper, we propose a simple yet effective model, "CCA+ICA", as a powerful tool for multi-task data fusion. This joint blind source separation (BSS) model takes advantage of two multivariate methods: canonical correlation analysis and independent component analysis, to achieve both high estimation accuracy and to provide the correct connection between two datasets in which sources can have either common or distinct between-dataset correlation. In both simulated and real fMRI applications, we compare the proposed scheme with other joint BSS models and examine the different modeling assumptions. The contrast images of two tasks: sensorimotor (SM) and Sternberg working memory (SB), derived from a general linear model (GLM), were chosen to contribute real multi-task fMRI data, both of which were collected from 50 schizophrenia patients and 50 healthy controls. When examining the relationship with duration of illness, CCA+ICA revealed a significant negative correlation with temporal lobe activation. Furthermore, CCA+ICA located sensorimotor cortex as the group-discriminative regions for both tasks and identified the superior temporal gyrus in SM and prefrontal cortex in SB as task-specific group-discriminative brain networks. In summary, we compared the new approach to some competitive methods with different assumptions, and found consistent results regarding each of their hypotheses on connecting the two tasks. Such an approach fills a gap in existing multivariate methods for identifying biomarkers from brain imaging data.
NeuroImage 05/2010; 51(1):123-34. · 5.89 Impact Factor
